Device and method for displacing glass plates during the machining of the same

ABSTRACT

A device for machining a glass plate ( 5 ) is provided with a lifting element ( 10, 11 ) which is used to lift the glass plate ( 5 ) from a transport device ( 3 ) located on a lower edge of a supporting wall ( 1 ), during the machining process. The lifting element ( 10, 11 ) includes lifting fingers ( 10 ) provided with clips ( 15 ) which can be applied to the lower horizontal edge ( 7 ) of the glass plate ( 5 ), in order to positively connect the lifting element ( 10, 11 ) to the glass plate ( 5 ). Both a drive for lifting and lowering the lifting element and a drive for horizontally displacing the same are associated with the lifting element ( 10, 11 ), such that the glass plate ( 5 ) can be displaced during the machining process, without slipping and without any time delay.

The invention relates to a device with the features of the introductorypart of claim 1.

The invention furthermore relates to a device for transport of a glasssheet which is to be worked.

When glass sheets are being worked, it is necessary or at leastdesirable for the glass sheets to be moved by exactly defined distancesand at the proper time to allow precision working.

This applies especially to the cutting of glass sheets using a waterjet, as is described for example in EP 1 110 686 A. When glass sheetsare to be cut using a water jet according to contours with any,therefore also curved outline shapes, it is especially important for theglass sheet to be moved in an exactly defined manner as it is beingworked (cutting using a water jet) in order to traverse the givencontour with the water jet in combination with movements of the nozzlefrom which the water jet is directed against the glass plate. In doingso changes of the direction of movement of the glass sheet are oftennecessary.

What was stated above for cutting of glass sheets with a water jet alsoapplies to the working of cut edges, for example those which have beenproduced by water jet cutting, by grinding with (diamond) grindingheads, in order to break or trim the cut edges. In this working what isimportant is to move the glass sheet exactly relative to the grindingtool.

Simple belt or roller conveyors are not able to accomplish thesemovements with sufficient precision, since both when braking and alsowhen accelerating slippage inevitably occurs between the conveyor beltsand the conveyor rollers which are provided with elastic jackets, andthe glass sheet. It was therefore proposed in EP 1 110 686 A that anentrainment device equipped with a suction head be allowed to engage theglass sheet which is to be cut using the water jet, as is known inprinciple from EP 0 123 009 A.

In any case such means which operate using suction heads for supportingthe movements of glass sheets have proven disadvantageous since thesuction head of the entrainment device is often “in the way” for workingof the glass sheet so that where the suction head engages the glasssheet the latter cannot be worked.

U.S. Pat. No. 5,086,907 A discloses a device for transporting archedglass sheets which are lying horizontally, which device is equipped witha so-called walking beam conveyor.

DE 37 18 859 A discloses a holding device for plate-shaped articles inwhich the articles are arranged on end. This holding device has clampingjaws which are tensioned against one another by springs in order to fixthe articles between them by friction.

The object of the invention is to make available a device and a processof the initially mentioned type with which glass sheets, even if theyare large and heavy, can be moved with precision while they are beingworked. In particular the device will also be suitable for moving glasssheets when they are cut using a water jet or when edges or cutouts inglass sheets are cut- or trimmed by a grinding head.

This object is achieved as claimed in the invention with a device and aprocess with the features of the independent claims.

Preferred and advantageous embodiments of the device as claimed in theinvention are the subject matter of the dependent claims.

In the device as claimed in the invention the glass sheet is raisedusing a lifting device off the conveyor means, for example the conveyorrollers, while it is leaning on the support wall and after inducing anon-positive connection between the lifting means and the glass sheet,the latter is moved precisely and without slip by the lifting means bythe distance required at the time in the direction required at the time.

The device as claimed in the invention is intended especially to moveglass sheets precisely in the horizontal direction; this is not possiblewith the movement of a glass sheet practiced in the past using conveyorrollers, since each time movement begins and each time movement endsslip occurs between the glass sheet and the conveyor means, for examplebelt conveyors or conveyor rollers which are coated with soft plastic(rubber-like).

Especially in devices for cutting of glass sheets using a water jet(water jet cutting) or when working glass sheets in order to grind theiredges or the edges of cutouts in them, a host of movements of the glasssheets which are to be exactly executed in the horizontal direction arenecessary so that in combination with vertical movements of the nozzlefrom which the water jet emerges, or of the grinding head, contours withany outline shape can be cut or worked by removal (grinding).

In one preferred embodiment the lifting means is made essentiallyrake-shaped, the glass sheets being lifted off the conveyor means by thelifting fingers which project from the base beam of the lifting means.

The non-positive connection between the lifting means and the glasssheet can be achieved in one embodiment by there being clamps on thelifting fingers, which clamps are placed against the lower edge of theglass sheet in order to cause the non-positive connection between thelifting means and the glass sheet.

The preferred devices can be combined into transport devices which arecomposed of several devices. Here the devices are arranged in succussionsuch that a glass sheet which is to be worked can be moved from onedevice to the adjacent device depending on the requirement. In this waythe lower horizontal edge of the glass sheet can also be worked. Inparticular the lower horizontal edge of the glass sheet can be ground orcan be provided with recesses. The working of the lower horizontal edgetakes place in a segment of the lower horizontal edge which is notoccupied by the lifting means.

Transfer from one device to the adjacent device takes place such thatthe glass sheet which is to be worked is always fixed in at least one ofthe lifting means during the working process. In this way the positionof the glass sheet with respect to the working tool is defined duringthe working process since the glass sheet is transferred without slip orplay from one device for working of the glass sheets to the adjacentdevice.

Other details, features and advantages of the invention arise from thefollowing description of one embodiment for a device as claimed in theinvention which is shown schematically in the drawings.

FIG. 1 shows a part of the device as claimed in the invention in anoblique view,

FIG. 2 shows a front view thereof,

FIG. 3 shows a view of the device with a glass sheet raised off theconveyor rollers,

FIG. 4 shows a side view thereof,

FIG. 5 shows a front view of the transport device which is composed oftwo devices which are shown in FIG. 1 to FIG. 4, and

FIG. 6 shows a front view of the second device from FIG. 5.

The device as claimed in the invention has a support wall 1 which istilted at the top somewhat to the rear, as is conventional in the glassdomain. In the support wall 1 there are several support rollers 2 whichare uniformly distributed over the surface of the support wall 1, whichcan be turned freely around an essentially vertical axis and which areequipped with an elastic thrust ring.

Basically any other type of support of the glass sheet 5 of the supportwall 1 is possible, for example, support rolls, air cushions, or thelike.

On the lower edge of the support wall 1 there is a conveyor means in theform of a row of conveyor rollers 3 which are driven in rotation aroundthe axes which are perpendicular to the plane of the support wall 1.Although in the embodiment the conveyor means consists of conveyorrollers 3, it is considered that the conveyor means consisting ofconveyor rollers 3 in this embodiment can be formed on the lower end ofthe support wall 1 also by a row of conveyor belts or by a conveyor beltwhich is deflected down at certain intervals to under the upper strand.

A glass sheet 5 is transported standing on the conveyor rollers 3 andleaning supported against the support wall 1 via the support rollers 2(direction arrow 6). The transport of a glass sheet 5 using the conveyorrollers 3 is used preferably for delivery of a glass sheet 5 which is tobe worked and to remove it after it is worked.

The situation with the glass sheet 5 standing upright on the conveyorrollers 3 and leaning on the support rollers 2 is shown again in FIG. 2(front view).

Like FIG. 1, FIG. 2 shows that between each conveyor roller 3 there is alifting finger 10 which is first located at a distance underneath thelower horizontal edge 7 of a glass sheet 5 which is standing on theconveyor rollers 3. The lifting fingers 10 are located on a common beam11 which together with them form a “lifting means” which can be movedboth essentially vertically (parallel to the plane of the support wall1; arrow 12) and also horizontally (arrow 13).

When the conveyor means is a series of belt conveyors, the liftingfingers 10 of the lifting means are each located between adjacentconveyor belts. In a conveyor belt which is deflected down in areas,there are lifting fingers 10 where the conveyor belt is deflected down.

First the beam 11 with the lifting fingers 10 (the lifting means whichis comprised of the beam 11 and the lifting fingers 10 is madeessentially in the manner of a rake) is raised in the direction of thearrow 12 until the lifting fingers 10 with their surfaces which point uprun up from underneath on the lower edge 7 of the glass sheet 5 and liftit off the conveyor rollers 3 as it continues to be lifted. Thesituation with the raised glass sheet 5 is shown in FIGS. 3 and 4.

In order to join the glass sheet 5 to the lifting fingers 10 of thelifting means (non-positively) there is a clamp 15 on individual liftingfingers 10 or on each lifting finger (see FIG. 4). These clamps 15 clampthe lower edge of the glass sheet 5 so that it follows, without slip,the horizontal movements (arrow 13) of the lifting means (beam 11 andlifting finger 10) when the glass sheet 5 is being worked and is to bemoved for this purpose (horizontally, back and forth).

In particular the clamp 15 can be swivelled on each lifting finger 10out of a jaw 16 which is joined fixed to the lifting finger 10 and aclamp jaw 17 which is supported on the free end of the lifting finger 10(axis 18). The jaws 16 and 17 can be provided on their areas whichadjoin the glass sheet 5 in the clamped position with supports ofelastic material.

To actuate the clamping jaws 17 which can be swivelled around the axes18 a hydraulic cylinder 19 is assigned to each clamp 15, is supported inthe area of the beam 11 and engages the extension of the clamp jaw 17which projects beyond the swivelling axis 18.

To move the lifting-means consisting of the lifting fingers 10 and thebeam 11 there can be any linear drives. Rack-and-pinion drives orspindle drives are preferred.

If the lift in the direction of the arrow 13 when a glass sheet 5 isbeing worked (for example, in water jet cutting) has to be larger thanthe maximum lift of the lifting means, the lifting means can be lowered,the glass sheet 5 settled on the conveyor rollers 3 and the liftingmeans can be lifted again after the lifting means moves back into itsinitial position (“drawback motion”) so that again the situation ofFIGS. 3 and 4 is reached and renewed movement of the glass sheet 5 inthe desired direction is possible.

In summary, one preferred embodiment of the device can be described asfollows.

In a device for working of a glass sheet 5 there is a lifting means 10,11 with which the glass sheet 5 while working can be lifted off theconveyor means 3 which is provided on the lower edge of a support wall1. The lifting means 10, 11 has lifting fingers 10 on which there areclamps 15 which can be placed against the lower horizontal edge 7 of theglass sheet 5 in order to non-positively join the glass sheet 5 to thelifting means 10, 11. The lifting means 10, 11 is assigned not only onedrive for raising and lowering it, but also a drive for its horizontalmovement so that the glass sheet 5 can be moved without slippage andwithout time delay as it is being worked.

The device which is described using FIGS. 1 to 4 can be combined in thetransport device which is shown in FIG. 5. This transport device insections I and II has one of the devices which is shown using FIGS. 1 to4. Here the same reference numbers in sections I and II designate partswhich correspond to one another. As in the device in section I thedevice in section II has a support wall I which is provided with supportrollers 2. Moreover the device in section II comprises a lifting means10, 11 with lifting fingers 10 which are attached to a beam 11.

FIG. 5 shows a front view of the transport device which has section Iand II at the time at which the glass sheet 5 is being transferred fromsection I into section II. The transfer process takes place as follows.

First the glass sheet 5 on the conveyor rollers 3 runs into section I.Then the lifting means 10, 11 in section I is raised and the glass sheet5 is held non-positively using the lifting fingers 10. The conveyorrollers 3 are thereupon lowered so that the glass sheet 5 is guided insection I by the lifting means 10, 11.

A free-standing section of the lower horizontal edge 7 of the glasssheet 5 can now be worked using a working tool 20, for example, adiamond grinding wheel, or using a water jet tool. The working tool 20can be moved between the sections I and II in the direction of the arrow21. To work the lower horizontal edge 7 of the glass sheet 5 the workingtool 20 is however in the position shown in FIG. 5.

While the lower horizontal edge 7 of the glass sheet 5 is being workedby the working tool 20, the lifting means 10, 11 moves as far aspossible up to the working-tool 20. The free-standing section of thehorizontal edge 7 then projects into section II of the transport device.In order to support the glass sheet 5, at this instant the conveyorrollers 3 in section II are raised in order to prevent the glass sheet 5from being detached from the lifting means 10, 11 in section I. Afterthe free-standing section of the horizontal edge has been worked, thelifting means 10, 11 in section II is raised and the glass sheet 5 isfixed in section II using the lifting means 10, 11. The conveyor rollers3 in section II are thereupon lowered and the conveyor rollers insection I are raised. The lifting means 10, 11 in section I can now bereleased and lowered so that it is possible to pull the glass sheet 5which is resting on the conveyor rollers 3 in section I into section II.As a result it is also possible now to work the remaining section of thehorizontal edge 7 using the working tool 20.

In doing so, under certain circumstances the problem arises that theadjustment path of the lifting means 10, 11 in section II is not enoughto work the entire remaining lower horizontal edge 7 of the glass sheet5. The lifting means 10, 11 in sections I and II are however also ableto encompass it. This is explained by way of example using FIG. 6.

Encompassing by the lifting means 10, 11 on the glass sheet 5 is carriedout by for example in section II the conveyor rollers 3 being raised andby the glass sheet 5 being settled on the conveyor rollers 3. In anotherprocess step the lifting means 10, 11 are set down and moved in asuitable manner in the direction of the arrow 13. Then the lifting means10, 11 in section II is raised again and the glass sheet 5 is fixed inthe lifting means 10, 11. After lowering the conveyor rollers 3 insection II the glass sheet 5 can be moved again along the support wall 1guided by the lifting means 10, 11.

As in the transfer process shown in FIG. 5, the encompassing processshown in FIG. 6 takes place without slip or play since the glass sheet5, while the lifting means 10, 11 is released from the glass sheet 5,rests on the conveyor rollers 3. The lifting means can therefore holdthe glass sheet 5 in the same position in which the lifting means 10, 11had set it down.

It should be noted that using the transport device shown in FIGS. 5 and6 glass sheets can be worked on all sides and over the surface up to alength of roughly 10 meters. The working of the glass sheets 5 on theedges takes place using grinding tools or using a water jet. The glasssheet 5 is worked over the surface preferably using a water jet.

1. Device for working of glass sheets (5) with a support wall (1) and aconveyor means (3) which is provided on the lower edge of the supportwall and on which a glass sheet (5) stands upright with its lowerhorizontal edge while it is leaning on the support wall (1),characterized in that a lifting means (10, 11) which can be fixed on theglass sheet (5) is assigned to the lower edge of the support wall (1),that the lifting means (10, 11) can be raised out of the readinessposition which is underneath the conveyor means (3) into an actionposition which is raised relative to the conveyor means (3), and whereinthe lifting means (10, 11) is assigned a drive for moving the liftingmeans (10, 11) in at least one direction (arrow 13) in the plane of thesupport wall (1).
 2. Device as claimed in claim 1, wherein the liftingmeans is made essentially rake-like with a base beam (11) and severallifting fingers (10) which project from it.
 3. Device as claimed inclaim 1, wherein there is at least one lifting finger (10) of thelifting means (10, 11) at a time between adjacent sections of theconveyor means (3).
 4. Device as claimed in claim 1, wherein theconveyor means is formed from a row of conveyor rollers (3) which are atleast partially driven in rotation.
 5. Device as claimed in claim 4,wherein the lifting fingers (10) of the lifting means are locatedbetween the conveyor rollers (3).
 6. Device as claimed in claim 1,wherein the conveyor means is formed from a row of sections of conveyorbelts.
 7. Device as claimed in claim 6, wherein the sections of theconveyor means are a sequence of conveyor belts which are located at adistance from one another, the lifting fingers (10) being locatedbetween the sections of the conveyor belts.
 8. Device as claimed inclaim 6, wherein the sections of the conveyor means are formed by acontinuous conveyor belt which is deflected down in the area of thelifting fingers (10) of the lifting means.
 9. Device as claimed in claim1, wherein on the lifting fingers (10) there are clamps (15) for fixinga glass sheet (5) on the lifting means (10, 11).
 10. Device as claimedin claim 9, wherein the clamps (15) have two clamp jaws (16, 17) on thelifting fingers (10).
 11. Device as claimed in claim 10, wherein atleast one (16) of the clamp jaws (15, 16) is rigidly connected to thelifting finger (10).
 12. Device as claimed in claim 10, wherein at leastone (17) of the clamp jaws (17, 16) can be swivelled relative to thelifting finger (10).
 13. Device as claimed in claim 9, wherein theclamps (15) of the lifting fingers (10) can be placed against the lowerhorizontal edge of a glass sheet (5).
 14. Device as claimed in claim 9,wherein the surfaces of the clamp jaws (16, 17) of the clamps (15),which surfaces can be placed against the glass sheet (5) are providedwith a support of elastic material.
 15. Device as claimed in claim 12,wherein the movable clamp jaw (17) of the clamp (15) is supported to beable to swivel around an axis (18) on the end of the lifting finger (10)which is remote from the base beam (11) of the lifting means (10, 11).16. Device as claimed in claim 1, wherein the drive for moving thelifting means is coupled to the base beam (11) of the lifting means (10,11).
 17. Device as claimed in claim 1, wherein there are separate drivesfor raising and lowering the lifting means (10, 11) on the one hand andfor horizontal movement of the lifting means (10, 11) on the other. 18.Transport device characterized by at least two successive devices asclaimed in claim
 1. 19. Transport device as claimed in claim 18, whereinduring a working process on the glass sheet (5) at least one liftingmeans (10, 11) can be fixed on the glass sheet (5) which is to beworked.
 20. Process for transport of a glass sheet (5) which is to beworked, characterized by the following process steps: placing the glasssheet (5) against a support wall (1) of a first device as claimed inclaim 1; fixing the glass plate (5) in the lifting means (10, 11) of thefirst device; transport of the glass sheet (5) to a second device;fixing the glass plate (5) in the lifting means (10, 11) of the seconddevice; and releasing the lifting device (10, 11) of the first device.